The P-3 service life extension program (SLEP) served to extend the P-3 s capabilities. The P-3 fulfilled a wide breadth of mission sets, ranging from overland ground troops support to littoral surveillance to hunting submarines. Answering the demand for multimission capability, the 24-year-old P-3 entered a sustained readiness program (SRP), extending its airframe from its current 29- year service life to its limited fatigue life of 38 years. Unexpected findings, however, arose during SRP. The P-3s had so much corrosion that SRP contract could not sustain the 221 aircraft fleet. As such, the aircraft went through a service life assessment program (SLAP) to determine not only the severity of the corrosion problem, but also the structural life remaining on the airframe. In addition, SLAP offered corrective structural remedies if the aircraft were suitable for SLEP. SLAP results were promising: The airframe can be extended by another lifetime. With new wings and a fatigue life management program, the P-3 could safely execute its missions for an additional two decades, satisfying the constant demand. Five years into SLEP, however, many P-3s were grounded due to out-of-tolerance wing cracks, leaving a third of its fleet on the ramp. This thesis analyzes the challenges of SLEP.